Acute carpal tunnel syndrome

Although the carpal tunnel is open at both ends, it has the physiologic properties of a closed compartment bounded by synovium proximally and distally. When the intracarpal canal interstitial pressure rises above a critical threshold pressure, capillary blood flow is reduced below the level required for median nerve viability. Acute carpal tunnel syndrome is recognized frequently as occurring secondary to wrist trauma and infrequently due to a variety of infectious, rheumatologic, and hematologic disorders. This condition warrants prompt recognition and the treatment is early carpal tunnel release.     

Reoperation for carpal tunnel syndrome

Although primary carpal tunnel release is usually successful, reoperation is needed in up to 3% of patients. Common indications of reoperation are previous incomplete surgery and postoperative fibrosis. Although most patients improve after reoperation, persistent systems are likely and failure is more frequent than after primary carpal tunnel surgery. Risk factors for failure following reoperation include the presence of an active Worker's Compensation claim, pain in the ulnar nerve distribution, and the absence of abnormality on preoperative EMG.     

Persistent or recurrent carpal tunnel syndrome following prior endoscopic carpal tunnel release

Immunohistochemistry was applied in the investigation of the possible existence of serotonin in human skin. It was found that epidermal melanocytes express a serotonin-like immunoreactivity. The immunoreactivity was associated with both the cytoplasm and the cellular membrane, though the latter was only found in certain cells. The serotonin anti-serum labeled the same cells as NKI-beteb, which is known as a reliable marker of melanocytes. Blocking experiments showed that both serotonin and NKI-beteb have different epitopes in the melanocytes. In in vitro studies, serotonin-like immunoreactivity appeared in approximately 90% of cultured human melanocytes, and was found both in the cytoplasm and also in the nuclei. Thus, we believe the melanocytes to be the origin of serotonin (or a serotonin-like molecule) in the skin.     

Predicting acute denervation in carpal tunnel syndrome

OBJECTIVE: Defects of the cochlear modiolus have been found to be associated with most cases of large vestibular aqueduct. The clinical significance of these modiolar defects has not been studied previously. The purpose of this article is to correlate clinical (functional) parameters, such as hearing outcomes, with the severity of the radiographic findings in these dysplastic inner ears. STUDY DESIGN: The study design was a retrospective chart review, supplemented with telephone interviews and clinic visits. SETTING: The study was conducted at an academic, tertiary care center. PATIENTS: Thirty consecutive patients with large vestibular aqueducts participated. RESULTS: Scores of modiolar deficiencies yielded inconsistent correlations with hearing loss. Vestibular aqueduct morphology and thickness correlated very strongly with the severity of hearing loss. CONCLUSIONS: These observations support the hypothesis that large vestibular aqueduct-related hearing loss may be caused by transmission of subarachnoid pressure forces into the inner ear. However, the thickness and morphology of the vestibular aqueduct may simply be markers for more subtle cochlear dysplasia manifest by modiolar deficiency.     

Silent period abnormalities in carpal tunnel syndrome

Zygosaccharomyces bailii inactivation was evaluated in oscillatory high hydrostatic pressure (HHP) treatments at sublethal pressures (207, 241, or 276 MPa) and compared with continuous HHP treatments in laboratory model systems with a water activity (aw) of 0.98 and pH 3.5. The yeast was inoculated into laboratory model systems and subjected to HHP in sterile bags. Two HHP treatments were conducted: continuous (holding times of 5, 10, 15, 20, 30, 60, or 90 min) and oscillatory (two, three, or four cycles with holding times of 5 min and two cycles with holding times of 10 min). Oscillatory pressure treatments increased the effectiveness of HHP processing. For equal holding times, Z. bailii counts decreased as the number of cycles increased. Holding times of 20 min in HHP oscillatory treatments at 276 MPa assured inactivation (< 10 CFU/ml) of Z. bailii initial inoculum. Oscillatory pressurization could be useful to decrease Z. bailii inactivation time.     

The nerve lesion in the carpal tunnel syndrome

The relative roles of pressure deformation and ischaemia in the production of compression nerve lesions remain a controversial issue. This paper concerns the genesis of the structural changes which follow compression of the median nerve in the carpal tunnel. The initial lesion is an intrafunicular anoxia caused by obstruction to the venous return from the funiculi as the result of increased pressure in the tunnel. This leads to intrafunicular oedema and an increase in intrafunicular pressure which imperil and finally destroy nerve fibres by impairing their blood supply and by compression. The final outcome is the fibrous tissue replacement of the contents of the funiculi.     

Screening for carpal tunnel syndrome in the workplace

Diaphragmatic crus lipoma is a very rare entity. In this case report, smooth, rounded masses of diaphragmatic lipoma, incidentally observed in a 37-year-old female on routine abdominal computed tomographic scanning is presented.     

Less common causes of carpal tunnel syndrome

A new DRB3*02 allele (DRB3*0207) was detected in a female Luxembourg Caucasian blood donor by sequence-based typing. The new allele differs from DRB3*0202 by two substitutions in codon 57 resulting in an amino acid change from a charged aspartic acid to a neutral valine. This is the first example of a DRB3 allele pair differing only at codon 57.     

The electrophysiological diagnosis of carpal tunnel syndrome

Electrophysiological investigations were carried out both in patients with carpal tunnel syndrome (CTS) and in healthy individuals. The evoked potentials were examined during stimulation of sensitive branches of n. medianus and of other nerves. The most sensitive and important for diagnosis appeared to be the electrophysiological test of alteration of responsive reaction to the stimulation of the sensitive branch of n. medianus for 4 finger and the considerable difference of evoked reactions on stimulation of skin palm branch and branch of the 1-st finger of n. medianus. The diagnostic importance of these indices corresponds well to anatomical and pathophysiological characteristics of CTS.     

High-resolution ultrasonography in the study of carpal tunnel syndrome

The cellular activity of hemocytes from the marine mollusc Mytilus galloprovincialis was studied using computer-assisted microscopic image analysis. PDGF-AB and TGF-beta 1 caused changes in cellular shape and induced the immunocytes to migrate in a chemotactic manner. The effect of PDGF-AB was more potent than that of TGF-beta 1, and the responses were dose-correlated for PDGF-AB, while they were dose-dependent up to 5 pg/ml for TGF-beta 1. Moreover, the PDGF-AB response was extracellular Ca(2+)-independent, while TGF-beta 1 was Ca(2+)-dependent.     

Functional psychomotor deficits associated with carpal tunnel syndrome

A reliable task was developed for investigating functional deficits associated with carpal tunnel syndrome (CTS). A rapid pinch and release psychomotor task utilizing muscles of the hand innervated by the median nerve was administered using a strain gauge dynamometer and providing limited force feedback. The motor performance characteristics studied were speed and force control. An experiment was conducted for studying the effects of force level, hand dominance, test-retest reliability, learning, and inter-subject variability using 13 subjects free from any hand disabilities or symptoms. A companion study was also conducted using 17 normal subjects and ten subjects diagnosed having CTS to investigate differences between CTS and control subjects. Dominant hands performed 4% to 8% better than the non-dominant hands by having a greater pinch rate, a smaller overshoot force, and less time above the upper force level and below the lower force level. Control subjects performed 25% to 82% better than CTS subjects. Age contributed 6% of the total variance for pinch rate and 7% of the total variance for the time below the lower force level. The results suggest that people suffering from CTS may experience similar functional psychomotor deficits in daily living and manual work activities.     

Re: Management of idiopathic carpal tunnel syndrome

A male fetus of gestation day 187 was aborted from a Holstein-Friesian cow in an epizootic of the Aino virus (AINOV) in September 1995. Neutralizing antibody titers against AINOV were 1:128, 1:16 and 1:64 in the dam serum, fetal ascites and cerebrospinal fluid, respectively. A 10% brain suspension of the aborted fetus was prepared immediately after autopsy, rinsed three times and sonicated before centrifugation. The supernatant was then inoculated into HmLu-1 cell cultures. A cytopathic effect was noted on post-inoculation day 7. The isolated virus was identified as the AINOV based on the physicochemical properties and cross neutralization test. This is the first report on the isolation of AINOV from an aborted bovine fetus.     

Histology of the transverse carpal ligament and flexor tenosynovium in idiopathic carpal tunnel syndrome

Histology of the transverse carpal ligament and flexor tenosynovium was investigated in 166 wrists from 130 patients with idiopathic carpal tunnel syndrome. Nine wrists from 9 controls were used for comparison. In the patients, 73.5% of the ligament and 56.0% of the tenosynovium showed normal histology. In the remaining specimens, the ligament showed mucoid change (17.5%), amyloid deposits (7.8%), inflammation (3.0%), and chondrometaplasia (2.4%), and the tenosynovium showed fibrosis (25.3%), edema (7.2%), inflammation (10.2%), amyloid deposits (8.4%), and vascular hypertrophy (4.8%). The majority of these changes were mild in degree and the pathophysiology did not appear to be meaningful. We conclude that in idiopathic carpal tunnel syndrome, the ligament and tenosynovium often show normal histology and there are no typical or consistent changes with which idiopathic carpal tunnel syndrome can be associated.     

The predictive value of electrodiagnostic studies in carpal tunnel syndrome

In recent years, electrodiagnostic studies have become an expected component in the work up and evaluation of carpal tunnel syndrome. We conducted a retrospective review of 460 carpal tunnel decompressions to determine whether the accuracy of diagnosis and the prediction of therapeutic outcome could be related to the positivity and severity of findings on preoperative electrical studies. The 349 patients (460 hands) were divided into two groups: group 1 consisted of hands with the clinical diagnosis of carpal tunnel syndrome but with normal electrodiagnostic studies (n = 62); in group 2 the hands had a clinical diagnosis of carpal tunnel syndrome with confirmatory electrodiagnostic studies (n = 398). The number and distribution of signs and symptoms of carpal tunnel syndrome were not statistically different between these two groups. There was not a statistically significant difference in the success rate of surgery or the incidence of complications. The similarities between these two groups suggests that the distinction between them (the positivity of electrodiagnostic studies) is an artificial one and that the clinical diagnosis of carpal tunnel syndrome is sufficient to predict the presence of the disease, as well as outcome of surgery. On the basis of these data, strict adherence to electrodiagnostic studies to confirm the diagnosis will exclude 13 percent of the patients with legitimate carpal tunnel syndrome from receiving appropriate therapy.     

Acute carpal tunnel syndrome secondary to pseudogout: case report

Acute carpal tunnel syndrome secondary to chondrocalcinosis seems not to have been previously reported. In a 75-year-old woman, with arthropathy and calcification of the triangular fibrocartilage of the wrist, hyperparathyroidism was suspected, but not proven. Hydroxyapatite and calcium pyrophosphate crystals were found together in the pathological specimen. The patient obtained complete relief from sectioning of the transverse carpal ligament.     

Predictive models of carpal tunnel syndrome causation among VDT operators

Gpx2 mRNA, encoding a selenium-dependent glutathione peroxidase (GPX-GI), has been found to be highly expressed in the gastrointestinal tract (GI) mucosal epithelium. In this study, we show that GPX-GI is produced in the mucosal epithelium of the adult rat GI tract and that the activity levels are comparable to that from GPX-1. Post-mitochondrial supernatant GPX activity from the mucosal epithelium of the complete length of the small intestine was partially purified. A sample enriched for putative GPX-GI was fractionated by SDS-polyacrylamide gel electrophoresis. Polypeptides of 21 kDa and 22 kDa were digested with trypsin. After resolving the tryptic peptides by high pressure liquid chromatography (HPLC), the major peaks were analyzed for their amino acid sequence by Microflow-HPLC-Tandem Mass Spectrometry and automated Edman degradation sequencing. Both methods revealed that the 21-kDa sample contained rat GPX-GI determined by the sequence homology with the deduced mouse GPX-GI polypeptide sequence. Rat GPX-1 was also detected in the samples. AntiGPX-GI and antiGPX-1 antibodies were used to determine the distribution of the respective isoenzyme activities along the length of the intestine and with respect to the crypt to villus axis in rats. GPX-GI and GPX-1 activities were uniformly distributed in the middle and lower GI tract and with respect to the crypt to villus axis. GPX-GI activity accounted nearly the same percentage of the total GPX activity as GPX-1 in all of the these compartments. Studies on the distal ileum segment of wildtype and Gpx1 gene knockout mice showed that GPX-GI activity was also at parity with GPX-1 in the mucosal epithelium of this segment.